This relates generally to electronic devices and, more particularly, to electronic devices with antennas.
Electronic devices often include antennas. For example, cellular telephones, computers, and other devices often contain antennas for supporting wireless communications.
Electronic devices often are required to support wireless communications in multiple frequency bands. With compact electronic devices such as mobile electronic devices, it can be challenging for antenna structures to support the various frequency bands while being limited by device area or volume constraints. One antenna is often required to handle communications in multiple frequency bands.
Front-end circuitry such as filters and switches are used to separate radio-frequency signals of different frequency bands that are received at a particular antenna. The front-end circuitry conveys receive and transmit signals between radio-frequency transceiver circuitry and one or more antennas. However, it can be challenging to ensure adequate wireless performance. For example, antennas may be located at different distances from the transceiver circuitry. An antenna located at a distance away from transceiver circuitry may require connection via a radio-frequency transmission line such as a coaxial cable. Antennas located at different distances may be subject to different amounts of signal loss, which adversely impacts wireless performance. Filters and switches may also impart different amounts of loss when conveying radio-frequency signals of different frequency bands. In addition, signals of different frequency bands can potentially cause interference due to nonlinear circuit operation.
It would therefore be desirable to be able to provide improved radio-frequency front end circuitry for wireless electronic devices.